Amphibious vehicle

ABSTRACT

An amphibious vehicle wheel suspension includes upper and lower linkages, road suspension means, and a retraction means for moving the wheel between a protracted position for road use and a retracted position for marine use. Suspension means can be operatively disconnected from the wheel and/or the linkages to allow for retraction and protraction. Retraction means may also be disconnected for road use. The disconnection mechanisms may comprise a ball and track mechanism, interlocking splines, interlocking teeth, or a pneumatic clutch. Also provided is a combination of splines for a suspension lever arm, and a pneumatic clutch for retraction arm Suspension means may be connected to upper linkage. Coil, torsion bar, or hydropneumatic springs may be used.

BACKGROUND OF THE INVENTION

The present invention relates to an amphibious vehicle.

Amphibious vehicles capable of powered travel on both land and water areknown. In order to improve the performance of amphibious vehicles onwater, various systems have been developed to allow the wheels to beretracted above the water line when the vehicle is water-borne. Such asystem is known, for example, from the applicants' International patentapplication WO95/23074, which describes an apparatus that enables anaxle-driven wheel to move between a protracted position, in which it hasa substantially horizontal axis of rotation for support of the vehicleon land, and a retracted position, in which the axis of rotation of thewheel is at an angle greater than 45 degrees to the horizontal.

In a typical known retractable wheel arrangement, the wheel is mountedto the body of the vehicle by means of one or more suspension linkageswhich are configured to allow the wheel to move between the protractedand retracted positions. Normally an actuator, such a hydraulic strut orram, will be operatively connected to one of the suspension linkages tomove the wheel between the protracted and retracted positions. Alsoconnected to one of the suspension linkages is a suspension meanscomprising springing and damping means for absorbing road shocks whenthe vehicle is used on land. Various types of suspension means have beenproposed for use with the known retractable wheel apparatus, such as:coil spring and hydraulic damper struts, torsion bar and damper systems,and hydropneumatic suspension units.

A drawback with known retracting wheel arrangements is that the designof the suspension means may have to be compromised in order to allow thewheel to be retracted. For example, it may be necessary to design thesuspension means so that it can be fully compressed when the wheelretracts or it may be necessary to alter the sizes and shapes ofcomponents to enable full retraction of the wheel to take place. As aresult, it may be difficult and time consuming to tune the suspensioncharacteristics of the vehicle for land use. For example, users of thevehicle will expect ride comfort characteristics on land which arecomparable to those of a conventional land based motor vehicle.

A further drawback of some known wheel retraction arrangements is theamount of space required to accommodate movement of the suspension meansas the wheel moves between its protracted and retracted positions. U.S.Pat. No. 4,958,584, for example, describes an amphibious vehicle havinga wheel retraction arrangement in which the wheel is attached to thevehicle body using a wishbone type suspension. A suspension means in theform of a strut having a coil spring located about a telescopichydraulic damper is connected between an upper wishbone and part of thewheel retraction system. To move the wheel to the retracted position,the upper end of the strut is drawn inwardly. This arrangement takes upa considerable amount of space in a central area of the vehicle makingit unsuitable for use with a compact amphibious vehicle. The problem ismost acute where the engine and transmission are mounted between a pairof retractable road wheels, as there is little space available intowhich the struts for those wheels can be drawn.

SUMMARY OF THE INVENTION

It is an object of the invention to provide an amphibious vehicle havinga retractable wheel arrangement in which the characteristics of thesuspension means can be more easily optimised for road use.

It is a further object of the invention to provide an amphibious vehiclehaving a retractable wheel arrangement in which less space is requiredto allow movement of the wheel between its protracted and retractedpositions.

It is yet a further object of the invention to provide an amphibiousvehicle having a retractable wheel arrangement where the suspensionspring does not have to be compressed in order to retract thesuspension.

In accordance with the invention, there is provided an amphibiousvehicle having a wheel mounted to a body of the vehicle so as to bemovable from a protracted position, for use of the vehicle on land, to aretracted position, in which the wheel is stowed for use of the vehicleon water, the vehicle further comprising a suspension means to absorbshocks from the wheel during land use and a retraction means for movingthe wheel between the protracted and retracted positions, characterisedin that the suspension means can be operatively disconnected from thewheel when the wheel is to be retracted.

Because the suspension means can be operatively disconnected from thewheel, the suspension means can be tuned to provide optimum road or landuse characteristics without having to compromise the design to enablethe wheel to be retracted. Furthermore, because the suspension means isdisconnected from the wheel, it can remain in its land use position whenthe wheel is retracted, eliminating the need to allow space toaccommodate movement of the suspension means as the wheel is retracted.

Preferably, the retraction means can be operatively disconnected fromthe wheel when the wheel is in the protracted position.

In a particularly preferred embodiment, the wheel is mounted to the bodyof the vehicle by means of one or more suspension linkages and thevehicle further comprises suspension disconnect apparatus foroperatively connecting the suspension means to, or operativelydisconnecting the suspension means from, one of the suspension linkages.

Preferably, the suspension means is operatively connected to one end ofa suspension lever arm, the other end of the suspension lever arm beingoperatively connectable to said one of the suspension linkages by thesuspension disconnect apparatus.

Preferably, the said one of the suspension linkages and the retractionlever arm are mounted to the vehicle body for pivotal movement relativeto the body about an axis and the suspension disconnect apparatuscomprises means movable between a first position, in which the said oneof the suspension linkages and the suspension lever arm are locked so asto pivot together about the axis, and a second position, in which thesaid one of the suspension linkages and the suspension lever arm arefree to pivot about the axis relative to one another.

In one preferred embodiment, the suspension disconnect apparatuscomprises a bore in the said one of the suspension linkages or in thesuspension lever arm, the bore having a number of ball receiving tracksformed over a part of its length, a shaft slidably mounted to the otherof the said one of the suspension linkages or the suspension lever arm,the shaft projecting into the bore and having a knuckle about which aremounted a plurality of balls, the shaft being movable from a firstposition in which the balls are engaged in the tracks to lock the saidone of the suspension linkages and the suspension lever arm together forpivotal movement about the axis and a second position in which the ballsare not engaged in the tracks and the said one of the suspensionlinkages and the other end of the suspension lever arm are free to pivotabout the axis relative to one another.

Preferably, the suspension disconnect apparatus comprises an actuator,which may be an hydraulic actuator, to move the shaft between the firstand second positions.

In an alternative embodiment, the said one of the suspension linkagesand the suspension lever arm have adjacent drive portions and thesuspension disconnect apparatus further comprises a sleeve having drivemeans for cooperation with corresponding drive means on the driveportions, the sleeve being movable from a first position in which it isin driving cooperation with both of the drive portions to lock the saidone of the suspension linkages and the suspension lever arm together forpivotal movement about the axis, and a second position in which it is indriving cooperation with only one of the drive portions such that thelinkage and the arm are free to pivot about the axis relative to oneanother.

Preferably, the sleeve is internally splined for engagement withcorresponding splines formed on the drive portions. Alternatively, abore of the sleeve may have a non-circular cross section for drivingengagement with correspondingly shaped profiles on the drive portions.

Preferably, the suspension disconnect apparatus comprises an actuator,which may be an hydraulic actuator, to move the sleeve between the firstand second positions.

In a yet further preferred embodiment, the said one of the suspensionlinkages and the suspension lever arm have corresponding drive teeth andthe suspension lever arm is movable between a first position in whichthe drive teeth are engaged so as to lock the said one of the suspensionlinkages and the suspension lever arm together for pivotal movementabout the axis, and a second position in which the drive teeth aredisengaged such that the said one of the suspension linkages and thesuspension lever arm are free to pivot about the axis relative to oneanother.

Preferably, the suspension disconnect apparatus comprises an actuator,which may be a hydraulic actuator, to move the suspension lever armbetween the first and second positions.

Preferably, the vehicle further comprises a retraction disconnectapparatus for operatively connecting the retraction means to, oroperatively disconnecting the retraction means from, one of thesuspension linkages.

Preferably, the retraction means comprises a retraction actuatoroperatively connected to one end of a retraction lever arm, the otherend of the retraction lever arm being connectable to said one of thesuspension linkages through the retraction disconnect apparatus.

Preferably, the said one of the suspension linkages and the retractionlever arm are mounted to the vehicle body for pivotal movement relativeto the vehicle body about an axis, the retraction disconnect apparatuscomprising means for locking the said one of the suspension linkages andthe retraction lever arm together for pivotal movement about the axis.

Advantageously, the retraction disconnect apparatus comprises apneumatic clutch.

In one preferred embodiment, the clutch connects the said one of thesuspension linkages and the retraction lever arm such that when theclutch is engaged the said one of the suspension linkages and theretraction lever arm are locked together for pivotal movement about theaxis and that when the clutch is disengaged, the said one of thesuspension linkages and the retraction lever arm are free to rotateabout the axis relative to one another.

In an alternative embodiment, the said one of the suspension linkages isrotationally fast with a shaft, the pneumatic clutch having a firstcomponent which is also rotationally fast with the shaft and a secondcomponent attached so as to be rotationally fast with the retractionlever arm, the clutch being adapted such that when it is engaged thefirst and second components are rotationally fast so as to lock the saidone of the suspension linkages and the retraction lever arm together forpivotal movement about the axis.

Preferably, the wheel is connected to the vehicle body by an uppersuspension linkage and a lower suspension linkage.

Preferably, the suspension means is connectable to the upper suspensionlinkage. Alternatively, the suspension means is connectable to the lowersuspension linkage.

Preferably, the retraction means is connectable to the lower suspensionlinkage.

Preferably, the suspension means comprises a strut having a coil springmounted about a telescopic hydraulic damper.

Preferably, the retraction means comprises a double acting fluid ram.Alternatively, the retraction means may be in the from of a electricallydriven ram.

BRIEF DESCRIPTION OF THE DRAWINGS

Several embodiments of an amphibious vehicle in accordance with theinvention will now be described, by way of example only, with referenceto the following drawings in which:

FIGS. 1A, 1B and 1C are respectively a side elevation, a plan view, anda rear elevation of an amphibious vehicle in accordance with theinvention:

FIG. 2 is a perspective, somewhat schematic view of a wheel suspensionand retraction apparatus of the amphibious vehicle of FIGS. 1A to 1C;

FIG. 3 is a cross-sectional view taken on line A-A of FIG. 2, showing afirst embodiment of a suspension disconnect apparatus of the apparatusof FIG. 2;

FIG. 4 is a view similar to that of FIG. 3 but showing a secondembodiment of a suspension disconnect apparatus of the apparatus of FIG.2;

FIG. 4A is an inset view showing in cross section a splined collarforming part of the second embodiment of the suspension disconnectapparatus;

FIG. 5 is a view similar to that of FIG. 3 but showing a thirdembodiment of a suspension disconnect apparatus of the apparatus of FIG.2;

FIG. 6 is a cross-sectional view taken on line B-B of FIG. 2, showing aretraction disconnect apparatus of the wheel suspension and retractionapparatus of FIG. 2;

FIG. 7 is a perspective, somewhat schematic view of a further embodimentof a suspension and retraction apparatus of the amphibious vehicle ofFIGS. 1A to 1C, and

FIG. 8 is a cross-sectional view taken on line C-C of FIG. 7, showingco-axial suspension and retraction disconnect apparatus of thesuspension and retraction apparatus of FIG. 7.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the drawings, in which like numerals have been used todenote common components throughout the several embodiment: FIGS. 1A, 1Band 1C show three views of an amphibious vehicle (generally indicated byarrow 1) comprising a body 2 being a buoyant vessel, having wheels 3(indicated by 3P for the protracted position, and 3R for the retractedposition). As shown this preferred embodiment has four wheels; however,other configurations, such as three wheels, or multiple wheels, arepossible.

The vehicle includes a motor 4 or similar power-source to provide powerthrough transmission 5 to differentials 6A (front) and 6B (rear), eachhaving drive-outputs 7, as shown. The motor 4 also provides powerthrough a gearbox 8 to a marine propulsion unit 9. Various combinationsof motors, transmissions and propulsion units can be assembled however,without change to the principle of the invention. The essentialfunctions of this invention would be suited to numerous configurationsof land-water amphibious vehicles.

A wheel-retraction apparatus is generally indicated by arrow 20.

In this preferred embodiment, FIGS. 1A, 1B and 1C further show thedrive-outputs 7 connected to the drive shafts 10, these being connectedto the wheels 3P and 3R respectively which are located to the body 2 (atfront and rear) by upper suspension linkages 11, and lower suspensionlinkages 12. These shafts and linkages operate in an upper compartment13 and a lower compartment 14 for each of the wheels. From the threeviews of FIG. 1 it will be understood that each wheel may process from alower (protracted) land-support position 3P to an upper (retracted)water-borne position 3R, wherein each wheel is largely enclosed withinits respective compartment 13.

FIG. 2, shows in more detail a first embodiment of a wheel suspensionand retraction apparatus 20 for an amphibious vehicle 1 in accordancewith the invention. The apparatus comprises a wheel support 16 having anopening or housing 21 for receiving a constant velocity (CV) joint of adrive shaft 10 (not shown in FIG. 2) to which a wheel, shown in outlineat 3, is mounted. In the case of a non-driven wheel, the wheel supportmay be in the form of a stub axle.

The wheel support is pivotably mounted to a frame of the body 2 of thevehicle (not shown in FIG. 2) by means of the upper 11 and lower 12suspension linkages which are arranged in a wishbone configuration knownin the automotive field. The upper wishbone 11 is pivotably connected toan upper end of the Wheel support 16 by means of an upper ball joint 22and is pivotably connected to the vehicle body by means of upper,inboard pivots 23, 24. Similarly the lower wishbone 12 is pivotablyconnected to the wheel support 16 by means of a lower ball joint 25 andto the vehicle body by means of lower, inboard pivots 26, 27. Theconfiguration of the upper and lower wishbones and the pivots enablesthe wheel to move between a protracted position and a retracted positionalong a trajectory indicated by line X.

A suspension means in the form of strut 28 is provided to absorb roadshocks from the wheel when the vehicle is used on land. The strut 28incorporates a coil spring, indicated schematically at 29, mounted abouta telescopic hydraulic damper 30, in a manner well known in theautomotive field. An upper end of the strut 28 is pivotably connected tothe vehicle body by means of a pivot 31 whilst the lower end of thestrut is mounted to an outer end of a suspension lever arm 32 by meansof a further pivot 33. The inner end of the suspension lever arm 32 isconnected to the vehicle body and to one of the arms 11A of the upperwishbone 11 through one of the inboard pivots 24 which connect the upperwishbone to the vehicle body. Apparatus, indicated generally at 34,interconnects the inner end 32A of the lever arm 32 and the upperwishbone 11 so as to permit the two to be operatively connected for useof the vehicle on land or operatively disconnected when the wheel is tobe retracted for use of the vehicle on water.

Details of various embodiments of the apparatus 34, otherwise known assuspension disconnect apparatus, will be described in more detail below.However, in general the suspension disconnect apparatus 34 isconstructed such that when the lever arm 32 and the upper wishbone 11are operatively connected by the apparatus 34, torque is transmittedbetween the two but when the upper wishbone 11 and the lever arm 32 aredisconnected, torque is not transmitted between the two.

The wheel suspension and retraction apparatus 20 also includes anactuator 35 for moving the wheel 3 between its protracted and retractedpositions. In the present embodiment, the actuator is in the form of adouble acting hydraulic ram, but other types of actuator could be used.For example, the actuator 35 could be a pneumatic ram or an electricallydriven ram. One end of the ram 35 is connected to the vehicle body bymeans of a pivot 36 whilst the other end of the ram 35 is pivotablyconnected to a first end of a retraction lever arm 37. A second end ofthe retraction lever arm 37 is connected to the lower wishbone 12 viaone of the inner pivots 26 which connect the lower wishbone to thevehicle body. In operation, the hydraulic ram 35 can be extended orretracted to apply a torque to the retraction lever arm 37 which in turnapplies a torque to the lower wishbone 12 to move the wheel between theprotracted and retracted positions.

Although it is not essential to the invention, it is preferable if theactuator 35 can be operatively disconnected from the lower wishbone 12,and hence the wheel 3, when the vehicle is used on land. Bydisconnecting the actuator 35 in this way, the suspension system isisolated from the actuator when the vehicle is used on land and thecharacteristics of the suspension system can be optimised for land andin particular road use. In order that the actuator 35 can be operativelydisconnected from the lower wishbone 12, the retraction lever arm 37 isconnected to the lower wishbone 12 by means of apparatus, indicatedgenerally at 38, which is adapted to enable the retraction lever arm 37and the lower wishbone to be operatively connected or disconnected. Anembodiment of the apparatus 38, which is also known as a retractiondisconnect apparatus, will be described in more detail below withreference to FIG. 6. However, the apparatus 38 could also be constructedso as to be the same as or similar to the apparatus 34 forinterconnecting the suspension lever arm 32 and the upper wishbone 11.

There will now follow, with reference to FIGS. 3 to 5, a description ofseveral different embodiments of the suspension disconnect apparatus 34for interconnecting the suspension lever arm 32 and the upper wishbone11. It will be appreciated that as indicated above, the arrangementsdescribed can be readily adapted for use in the retraction disconnectapparatus 38 interconnecting the retraction lever arm 37 with the lowerwishbone 12. There will also follow with reference to FIG. 6, adescription of a retraction disconnect apparatus 38 for interconnectingthe retraction lever arm 37 and the lower wishbone 12. It should also beappreciated that the apparatus 38 could be adapted for use ininterconnecting the suspension lever arm 32 with the upper wishbone 11.

A first embodiment of the apparatus 34 indicated generally at 34′ isshown in FIG. 3. Part of the frame of the vehicle body is indicated at39. The vehicle frame is provided with two housings 40 for receivingbushes 41, 42, to which an inner end 43 of one of the arms 11A of theupper wishbone 11 and the inner end 32A of the suspension lever arm 32are respectively mounted. At least one housing 40 may be detachable fromthe frame 39 to facilitate assembly.

The inner end 43 of the upper wishbone arm 11A provides a housing 44having a blind bore 45. A hollow circular boss 46 projects axially fromthe closed end of the housing 44 and is pivotably received in one of thebushes 41. The open end of the bore 45 has a slightly enlarged diameterportion 47 on which is seated a bearing 48 in abutment with a lip 49between the enlarged diameter portion 47 and the remainder of the bore45. The bearing 48 is held in position on the housing by a circlip 50. Anumber of ball receiving tracks 51 are formed in the bore 45 inwardly ofthe lip 49. The tracks 51 extend only over a partial region of the bore45 for reasons which will be explained later.

The inner end or hub 32A of the suspension lever arm 32 has a generally“T” shaped cross section as shown in FIG. 3. On one axial end of the hub32A is a first circular boss region 52 which is pivotably receivedwithin the other of the bushes 42 on the vehicle frame. The opposite endof the hub 32A is received within the housing 44 and has a second bossregion 53, to which is mounted an inner race of the bearing 48. Theinner race of the bearing 48 is held in position on the second bossregion in abutment with an axial face 54 on the lever arm 32 by means ofa further circlip 55. The arrangement of the bearing 48 and the circlips50, 55 serves to locate the suspension lever arm 32 and the upperwishbone 11 axially relative to one another whilst permitting relativerotational movement between the two about the axis of rotation which isindicated at 56.

A bore 57 extends through the hub 32A. The bore has a first portion 58which is splined to mate with splines 59 formed along part of the lengthof a shaft 60 slidably mounted in the bore 57. The bore 57 also has asecond portion of enlarged diameter which is adapted to provided ahydraulic cylinder 62. The outer end of the cylinder is closed off bymeans of a cap member 63 which is in screw threaded engagement with thecylinder. The shaft 60 extends into the cylinder 62 and mounted to theend of the shaft 60 within the cylinder 62 is a piston 64. The piston 64sealingly engages the surface of the cylinder 62 to divide the cylinderinto two chambers 65, 66. A seal 67 in the cylinder 62 preventshydraulic fluid within the chamber 65 from entering the first portion 58of the bore 57 around the shaft 60. A first port 68 in the cap 63communicates with the chamber 66 on one side of the piston 64, whilst asecond port 69 communicates with the chamber 65 on the other side of thepiston.

The end of the shaft 60 opposite from the piston 64 extends from thelever arm hub 32A into the housing 44 and has a knuckle 70. A number ofsteel balls 71 are disposed about the knuckle 69 and mall be retained onthe knuckle by means of a cage (not shown). With the shaft 60 in theposition shown in FIG. 3, the steel balls 71 are engaged in respectivetracks 51 in the housing 44 and serve to transmit movement and forcesbetween the housing 44 and the shaft 60. This arrangement is similar tothat used in plunge type CV joints which will be familiar to thoseskilled in the art of automotive technology. Since the shaft 60 issplined to the suspension lever arm 32, torque can be transmittedbetween the lever arm 32 and the upper wishbone 11 through the splines59, the knuckle 70, steel balls 71T and the tracks 51, such that thesuspension strut 28 and the wheel 3 are operatively connected.

As mentioned above, the tracks 51 in the housing 44 extend only overpart of length of the bore 45 such that an inner region 72 of the bore45 has no tracks. The shaft 60 can be reciprocated axially within thebore 57 of the lever arm hub 32A to move the knuckle 70 and the steelballs 71 between the position shown in FIG. 3 and a position in whichthey lie within the inner, trackless region 72. In this position thesteel balls are no longer engaged in the tracks 51 and hence do not actto transmit movement and forces between the housing 44 and the shaft 60.Since no forces can be transmitted between the lever arm 32 and theupper wishbone 11, the suspension means or strut 28 is operativelydisconnected from the wheel 3.

Reciprocal movement of the shaft 60 is effected bad means of the piston64 in the cylinder 62. By connecting the chamber 66 to a source ofpressurised hydraulic fluid via the port 68 and connecting the chamber65 to a hydraulic fluid reservoir via the port 69, the piston 64 andshaft 60 can be moved to the left (as viewed in FIG. 3) until theknuckle 70 and steel balls 71 are in region 72 of the bore 45 having notracks and the lever arm 32 is operatively disconnected from the upperwishbone 11. This can be considered as a neutral stage in which theapparatus 34′ is disengaged. By reversing the hydraulic connections tothe chambers 65, 66, the piston and shaft can be moved to the right (asviewed) until the balls re-enter the tracks and the lever arm 32 isagain operatively connected with the upper wishbone 11.

Whilst use of a hydraulic piston and cylinder actuator is the preferredmeans for reciprocating the shaft 60, this is not essential and anysuitable means could be used. For example, a pneumatic, orelectromagnetic actuator could be used to reciprocate the shaft 60.

A second embodiment of a suspension disconnect apparatus 34″ forinterconnecting the suspension lever arm 32 and the upper wishbone 11 isshown in FIG. 4. A shaft 80 is rotatably mounted between the two bushes41, 42 on the vehicle frame. The inner end 43 of one of the arms 11A ofthe upper wishbone 11 and the suspension lever arm hub 32A are pivotablymounted to the shaft 80 between the bushes 41, 42 by means of bores 81,82. Bearings 83, 84 are fitted about reduced diameter end portions 85,86 of the shaft 80 where it extends through the bushes 41, 42. Thebearings 83, 84 are held in position by nuts 87 and washers 88 mountedon threaded studs 80A projecting axially from the ends of the shaft 80.The bearings 83, 84 locate thrust washers 89, 90 on the shaft, holdingthem in contact with the axially outer end faces of the wishbone arminner end 43 and the hub 32A. A further thrust washer 91 is locatedbetween the axially inner ends of the wishbone arm inner end 43 and thehub 32A. This arrangement locates the wishbone arm and the suspensionlever arm aerially between the bushes 41, 42 whilst permitting them torotate about the shaft relative to the vehicle body and, whendisconnected, to each other.

Axially inner portions 92, 93 of the wishbone arm inner end 43 and thelever arm hub 32A have a reduced diameter and are formed withcorresponding splines 92A, 93A. The splined portion 93 of the lever armhub 32A is arranged to be about twice the length of the splined portion92 on the wishbone arm. A sleeve 95 is provided about the splinedportion 93 on the lever arm hub 32A and has corresponding splines 96 onan inner surface, as shown in the cross section in FIG. 4A, whichdrivingly engage with the splines 93A of the hub 32A. When the sleeve isin the position shown in FIG. 4, it is in engagement only with thesplines 93A on the suspension lever arm hub 32A so that the upperwishbone 11 and the suspension lever arm 32 are free to rotate about theshaft 80 relative each other. Thus the suspension lever arm 32 isoperatively disconnected from the upper wishbone 11.

When the splines 92A, 93A on the upper wishbone 11 and the suspensionlever arm hub 32A are in alignment, the sleeve 95 can be moved to theleft (as viewed) so that the splines 96 in the sleeve 95 engage partlywith the splines 92A on the wishbone and partly with the splines 93A onthe suspension lever arm hub 32A. In this position the collar 95 locksthe upper wishbone arm 11A and the suspension lever arm 32 together sothat torque can be transmitted between them, operatively connecting thewheel 3 to the suspension strut 29.

The term “spline” as used herein should be understood to encompass anysuitable, elongate drive formations that would enable drive to betransmitted between the sleeve 95 and the inner, or drive, portions 92,93 of the wishbone arm inner end and the lever arm hub 32, whilstenabling the sleeve to move axially relative to the drive portions. Forexample, the sleeve 95 and the drive portions 92, 93 could be providedwith “splines” in the form of inter engaging gear teeth. Furthermore,whilst it is preferred that the sleeve 95 and the drive portions 92, 93are provided with corresponding spline formations, any other suitabledrive means can be provided between the sleeve 95 and the drive portions92, 93. For example, the portions 92, 93 could have a non-circularprofile, square or hexagonal for example, and the sleeve 95 can beprovided with a correspondingly shaped bore such that torque can betransmitted between the sleeve and the drive portions 92, 93.

Reciprocal axial movement of the sleeve 95 to connect and disconnect thelever arm 32 and the upper wishbone 11 can be effected by any suitablemeans. In the present embodiment it is effected by means of a hydraulicactuator having a cylinder 97 and a piston 98 which divides the cylinderinto two chambers 99, 100, one on either side of the piston. The pistonis connected to the sleeve by a selector shaft 101 attached to a lug 102on the sleeve 95 by means of a clevis pin 103. By appropriatelyconnecting one or other of the chambers 99, 100 to a source ofpressurised hydraulic fluid and the other chamber to a hydraulic fluidreservoir, the piston can be selectively moved to the left or right (asviewed) to connect and disconnect the suspension lever arm 32 and theupper wishbone 11 as required, thus engaging and disengaging theapparatus 34″.

A third embodiment of the apparatus 34′″ is shown in FIG. 5. A shaft 105is rotatably mounted in the bushes 41. 42 on the vehicle frame. Theinner end 43 of one of the arms 11A of the upper wishbone 11 and the hub32A of the suspension lever arm 32 are pivotably mounted to the shaft105 between the bushes 41, 42. A first set of drive teeth 106 areprovided on an axially inner face 107 of the inner end 43 of the upperwishbone arm 11A and a corresponding set of drive teeth 108 are providedon an axially inner face 109 of the hub 32A of the suspension lever arm32. The arrangement is such that the inner end 43 of the upper wishbonearm 11A is axially fixed relative to the shaft 105 whilst the hub 32A ofthe lever arm is adapted to slide reciprocally along the shaft so thatthe teeth 106, 108 can be brought into and out of engagement with eachother to operatively connect the suspension lever arm 32 with ordisconnect the suspension lever arm from, the wishbone arm 11A.

The shaft 105 has first and second regions 105A and 105B at either endwhich have a relatively small diameter and which are received in thebushes 41, 42. A third region 105C adjacent the first region 105A has aslightly enlarged diameter, whilst a fourth central region 105D betweenthe third 105C and the second 105B regions has an even larger diameter.

The inner end 43 of the upper wishbone arm 11A is rotatably mountedabout the third region 105C of the shaft 105 with its axially inner face107 in contact with a thrust washer 110 which itself is in abutment withan axial face 111 formed between the third region 105C and the central,fourth region 105D of the shaft. The inner end 43 of the upper wishbonearm 11A is located axially on the shaft by means of a bearing 112located about the first region 105A of the shaft. The axially inner endof the bearing 112 engages with a further thrust washer 113 to hold thethrust washer in contact with an axially outer face 114 of the inner end43 of the upper wishbone arm 11A. The bearing 112 is secured to theshaft by means of a nut 115 and washer 116 mounted to a threaded studportion 105E on the end of the shaft 105.

The hub 32A of the suspension lever arm 32 has a bore 117 which isadapted to be a sliding fit over the central, fourth region 105D of theshaft 105. An axially outer portion of the bore 117 is enlarged to forma cylinder 118 located about the second region 105B of the shaft. Apiston 119 is mounted on the second region 105B of the shaft and is heldin contact with an axial face 120 formed between the second and fourthregions 105B, 105D of the shaft by means of a further bearing 122. Aswith the bearing 121, the further bearing 122 is secured to the shaft105 by a nut 115 and washer 116 mounted to a threaded stud portion 105Eon the end of the shaft.

A closure member 123 is in threaded engagement with the enlargeddiameter portion of the bore 117 in the lever arm hub 32A to close thecylinder 118. The closure member has an inner bore 124 which is asliding fit about the bearing 122. Seals 125 are provided to sealbetween the closure member 123 and the bearing 122 to prevent hydraulicfluid leaking from the cylinder 118. The piston 119 divides the cylinder118 into two chambers 126, 127 and ports 128, 129 are provided in thehub 32A to allow each of the chambers to be selectively connected toeither a source of pressurised hydraulic fluid or to a hydraulic fluidreservoir.

FIG. 5 shows the apparatus 34′″ with the suspension lever arm 32 and theupper wishbone arm 11A operatively disconnected, i.e. with the apparatus34′″ disengaged. In this position the lever arm 32 is at its extremeright hand (as viewed) position with the driving teeth 106, 108disengaged so that the upper wishbone is able to pivot about the shaft105 relative to the suspension lever arm 32. By connecting the chamber126 to a source of pressurised hydraulic fluid and the chamber 127 to ahydraulic fluid reservoir the suspension lever arm 32 can be movedaxially to the left (as viewed) along the shaft 105 to engage the driveteeth 106, 108 with each other. When the drive teeth 106, 108 areengaged they lock the upper suspension linkage 11 and the suspensionlever arm 32 together for rotation about the shaft 105 and its axis 56.In this position torque can be transmitted between the upper wishbone 11and the suspension lever arm 32, operatively connecting the suspensionstrut 28 to the wheel 3. The driving teeth can be disengaged byreversing the hydraulic connections to the chambers 128, 129 to move thesuspension lever arm to the right (as viewed) to return it to theposition shown in FIG. 5.

To ensure that the hub 32A is able to slide freely on the shaft 105, anelasticated or neoprene boot 130 can be provided between the hub 32A andthe inner end 43 of the upper wishbone arm 11A to prevent water and dirtfrom coming into contact with the central, fourth region 105D of theshaft 105.

In this embodiment, the axial movement of the suspension lever arm mustbe accommodated by the suspension strut 28. To that end the strut 28 maybe mounted to the lever arm and/or to the vehicle body using compliantbushes.

FIG. 6 shows an embodiment of a retraction disconnect apparatus 38 forinterconnecting the retraction lever arm 37 and the lower wishbone 12. Ashaft 131 is mounted between two bushes 132, 133 attached to a frame 134of the vehicle body. An inner end 135 of one of the arms 12A of thelower wishbone and the inner end 37A of the retraction lever arm 37 arerotatably mounted to the shaft 131 between the bushes by means of bores136, 137.

A clutch 138 is connected by means of flanges 139, 140 between the lowerwishbone arm 12A and the retraction lever 37. The clutch is adapted totransmit torque between the lower wishbone arm 12A and the retractionlever arm 37 when it is engaged, to operatively connect the hydraulicretraction actuator 35 to the wheel 3. When the clutch 138 isdisengaged, the lower wishbone arm 12A and the retraction lever arm 37are free to pivot about the shaft 130 relative to each other.

Any suitable clutch 138 can be used provided it has sufficient capacityto transmit the forces required to move the wheel between the protractedand retracted positions. Since the detailed construction of the clutch138 is not a feature of the present invention it will not be described.In a particularly preferred embodiment the clutch 138 is a pneumaticclutch such as model No. 5H30 which can be obtained from Nexen Group,Inc., 560, Oak Grove Parkway, Vadnais Heights, Minn. 55127, USA. Thisclutch requires 80 psi air pressure to an internal actuating piston andis rated to transmit 210 Nm.

The assembly of the inner ends 135, 37A of the lower wishbone arm 12Aand the retraction lever arm 37 and the clutch 138 is axially located onthe shaft by means of bearings 141 located about reduced diameter endportions of the shaft 130. The bearings 141 are secured to the shaft bynuts 142 and washers 143 mounted to threaded spigots 131A at the ends ofthe shaft and hold thrust washers 144 in contact with respective axialend faces 145, 146 of the lower wishbone arm 12A and the retractionlever arm 37.

It will be appreciated that the apparatus 38 described above could beadapted for use as apparatus 34 for connecting and disconnecting thesuspension lever arm 32 and the upper wishbone 11 by incorporating aclutch capable of transmitting the suspension forces.

Operation of the suspension and retraction apparatus 20 when anamphibious vehicle enters and leaves the water will now be described.

As a vehicle approaches the water, the wheels 3 will be in theprotracted position and the suspension disconnect apparatus 34 will beengaged so as to operatively connect the suspension strut 29 with theupper wishbone 11 and the wheel 3. Hence suspension loads will betransmitted between the wheel and the suspension strut through the wheelsupport 16, the upper ball joint 22, the upper wishbone 11, and thesuspension lever arm 32. At this stage the retraction disconnectapparatus 38 is disengaged so that the retraction lever arm 37 isoperatively disconnected from the lower wishbone 12.

As the vehicle enters the water, the load comes off the suspension andthe wheel 3 droops. When the suspension is fully unloaded, thesuspension disconnect apparatus 34 can be disengaged to operativelydisconnect the suspension lever arm 32 from the upper wishbone 11. Theretraction lever arm 37 can then be operatively connected to the lowerwishbone 12 by engaging the apparatus 38, which in the presentembodiment is the pneumatic clutch 138. The hydraulic actuator 35 canthen be activated to move the wheel to the retracted position, with thesuspension strut 28 remaining in the road use position.

Although in the embodiment described above, the apparatus 34 isdisengaged to operatively disconnect the suspension lever arm 32 fromthe upper wishbone 11 before the retraction lever is connected to thelower wishbone 12, this need not be the case. In certain circumstancesit may be desirable to connect the retraction lever arm 37 to the lowerwishbone 12 before disconnecting the suspension lever arm 32 from theupper wishbone 11.

If required, means may be provided to prevent the suspension strut 28from extending when the suspension lever arm 32 is disconnected from theupper wishbone 11. For example, a limiting rod may be provided or thelength of the damper may be designed to prevent over extension of thestrut.

When the vehicle is to leave the water, the above procedure is reversed.The hydraulic actuator 35 is extended to move the wheel to theprotracted position. Once the wheel is fully extended the retractionlever arm 37 is disconnected from the lower wishbone 12 by disengagingapparatus 38 and the suspension lever arm 32 connected to the upperwishbone 11 by engaging the apparatus 34. Once the suspension means 28has been reconnected to the wheel 3, the vehicle can be driven towardsthe land and out of the water.

In certain circumstances it mars be desirable to engage the apparatus 34to reconnect the suspension lever arm 32 to the upper wishbone 11 beforethe apparatus 38 is disengaged. It may be advantageous for example, touse the retraction actuator 35 to ensure that the upper wishbone 11 andthe suspension lever arm 32 are held in predetermined relative positionsto enable the apparatus 34 to be engaged.

In the above described embodiment of the wheel suspension and retractionapparatus 20, the main suspension loads are taken between the upperwishbone 11 and the wheel support 16 via the upper ball joint 22.However, in order to allow the wheel 3 to be retracted and to also allowfor steering movement it is necessary for the upper ball joint to bepositioned horizontally. This arrangement may not be suitable forhandling high suspension down forces. FIG. 7 shows a further embodimentof a wheel suspension and retraction apparatus 20′ for an amphibiousvehicle 1 in which this problem is avoided by connecting both thesuspension means 28 and the retraction actuator 35 to the lower wishbone12.

The apparatus 20′ is similar to the apparatus 20 in that it comprises awheel support 16 pivotably connected to the vehicle body by means ofupper 11 and lower 12 wishbones. The apparatus 20′ differs in that boththe suspension strut 28 and the retraction actuator 35 are arranged tobe selectively connectable to one of the arms 12A of the lower wishbone12 by means of apparatus indicated generally at 150 which isincorporated into one of the inboard pivots 27 that connects the lowerwishbone 12 to the vehicle body.

The apparatus 150 which effectively is a co-axial suspension andretraction disconnect apparatus, can be seen best in FIG. 8. A shaft 151is rotatably mounted in three bushes 152-154 attached to a frame 155 ofthe vehicle body. The inner ends 156, 32A of one of the arms 12A of thelower wishbone 12, and of the suspension lever arm 32 respectively aremounted to the shaft between a first 152 and a second 153 of the bushes.The lower wishbone arm 12A is fixed rotationally fast with the shaft 151by means of a key 180, whereas the inner end 32A of the suspension leverarm is able to rotate about the shaft. Suspension disconnect apparatus,indicated generally at 157, is provided to selectively lock the innerend 32A of the suspension lever arm to the inner end 156 of the lowerwishbone arm 12A for rotation together about the shaft 151 and its axis56.

In the present embodiment, the suspension disconnect 157 is similar tothe apparatus 34″ described above in relation to FIG. 4. To this endcorresponding splines 160, 161 are provided on the lower wishbone arm 11and the suspension lever arm 32 and an internally splined collar 162 isaxially movable between the position shown in FIG. 8 in which it engagesonly with the splines 161 of the suspension lever arm 32, and a positionin which it engages with the splines 160, 161 on both the suspensionlever arm 32 and the lower wishbone arm 12A to lock the two together.Movement of the collar is effected by means of a hydraulic actuator 163which is connected to the collar 162 by means of a selector shaft 164and a clevis pin 165.

An inner end 37A of the retraction lever arm 37 is rotatably mounted tothe shaft 151 between the second 153 and the third 154 of the bushes bymeans of a bearing 166. The housing 167 of a pneumatic clutch 168 isattached to a flange 169 on the retraction lever arm 37 by means of aseries of bolts 170 so as to rotate with the lever arm 37. An output hub(not shown) of the clutch is fixed rotationally fast with the shaft 151by means of a key 171 such that when the clutch 168 is engaged the innerend 37A of the retraction lever arm 37 is locked rotationally fast withthe shaft 151.

Bearings 172-174 and thrust washers 175-179 serve to locate the innerend 156 of the lower wishbone arm 12A the inner end 32A of thesuspension lever arm 32 the inner end 37A of the retraction lever arm 37and the clutch 168 axially on the shaft 151.

Operation of the wheel suspension and retraction means 20′ will now bedescribed. When the vehicle is used on land pivotal movement of thelower wishbone 12 relative to the vehicle body due for example to thewheel 3 going over bumps in a road surface, is transmitted to the shaft151 via the key 180. The suspension lever arm 32 is rotationally lockedwith the lower wishbone arm 12A by the splined collar 162 which is movedto the left (as viewed in FIG. 8) so as to engage with the splines 160,161 on both the lower wishbone arm 12A and the suspension lever arm 32.Torque is therefore, transmitted between the suspension lever arm 32 andthe lower wishbone 12 to operatively connect the suspension strut 28with the lower wishbone 12 and hence the wheel 3. At this stage, thepneumatic clutch 168 is disengaged so that lever arm 37 can pivot aboutthe shaft 151 to isolate the retraction actuator 35 from the lowerwishbone 12.

When the vehicle enters the water, the mass of the vehicle is taken bythe water reducing the load on the suspension and allowing the wheel 3to droop. When the load on the suspension has been fully removed, thecollar 162 is moved to the right (as viewed) to the position shown inFIG. 8 in which the splines in the collar are in engagement with thesplines 161 on the suspension lesser arm 32 only. In this position, thesuspension lever arm 32 is free to pivot about the shaft 151 relative tothe lower wishbone arm 12 and the suspension strut 28 is operativelydisconnected from the lower wishbone 12 and the wheel 3. To retract thewheel 3 the pneumatic clutch 168 is engaged locking the retraction leverarm 37 to the shaft 151. The hydraulic ram 35 can then be activated topivot the retraction lever arm 37 turning the shaft 151 via thepneumatic clutch 168 and key 171. The lower wishbone 12, which isrotationally fast with the shaft 151 will then be pivoted upwardlyrelative to the vehicle body to move the wheel 3 to the retractedposition. The pneumatic clutch 168 may be engaged either before or afterthe suspension lever arm 32 is disconnected from the lower wishbone 12as required.

When the vehicle is to leave the water, the retraction actuator 35 isextended with the clutch 168 engaged so pivoting the lower wishbonedownwardly relative to the vehicle body to move the wheel 3 to theprotracted position. When the wheel is fully lowered, the pneumaticclutch 168 can be disengaged and the suspension strut 28 re-connected bymoving the splined collar 162 to the left (as viewed) to again lock thelower wishbone arm 12A and the suspension lever arm 32 together.

Depending on the specific design of the suspension arrangement, it maybe possible for the clutch 168 to be disengaged when the wheel is in thefully retracted position without the wheel moving back to the protractedposition. In such an arrangement, it will be necessary to re-engage theclutch 168 when it is desired to lower the wheel to the protractedposition.

Whereas the invention has been described in relation to what ispresently considered to be the most practical and preferred embodiments,it is to be understood that the invention is not limited to thedisclosed arrangements but rather is intended to cover variousmodifications and equivalent constructions included within the spiritand scope of the invention. For example, the suspension means need notbe a strut comprising a coil spring mounted about a telescopic hydraulicdamper but could be of any suitable form. The suspension means could,for example, be in the form of a torsion bar and damper or ahydropneumatic suspension system. Furthermore, the retraction actuatorneed not be a double acting hydraulic ram but could comprise a pneumaticactuator, a screw driven actuator, or indeed any suitable form ofactuator.

1. An amphibious vehicle having a wheel mounted to a body of the vehicleso as to be movable from a protracted position, for use of the vehicleon land, to a retracted position, in which the wheel is stowed for useof the vehicle on water, the vehicle further comprising a suspensionmeans to absorb shocks from the wheel during land use and a retractionmeans for moving the wheel between the protracted and retractedpositions, characterised in that the suspension means can be operativelydisconnected from the wheel when the wheel is to be retracted.
 2. Anamphibious vehicle as claimed in claim 1, in which the retraction meanscan be operatively disconnected from the wheel when the wheel is in theprotracted position.
 3. An amphibious vehicle as claimed in claim 1, inwhich the wheel is mounted to the body of the vehicle by means of one ormore suspension linkages, the vehicle further comprising suspensiondisconnect apparatus for operatively connecting the suspension means to,or operatively disconnecting the suspension means from, one of thesuspension linkages.
 4. An amphibious vehicle as claimed in claim 3, inwhich the suspension means is operatively connected to one end of asuspension lever arm, the other end of the suspension lever arm beingoperatively connectable to said one of the suspension linkages by thesuspension disconnect apparatus.
 5. An amphibious vehicle as claimed inclaim 4, in which the said one of the suspension linkages and the leverarm are mounted to the vehicle body for pivotal movement relative to thebody about an axis, the suspension disconnect apparatus comprising meansmovable between a first position in which the said one of the suspensionlinkages and the suspension lever arm are locked so as to pivot togetherabout the axis and a second position in which said one of the suspensionlinkages and the suspension lever arm are free to pivot about the axisrelative to one another.
 6. An amphibious vehicle as claimed in claim 5,in which the suspension disconnect apparatus comprises a bore in thesaid one of the suspension linkages or in the suspension lever arm, thebore having a number of ball receiving tracks formed over a part of itslength, a shaft slidably mounted to the other of the said one of thesuspension linkages or the suspension lever arm, the shaft projectinginto the bore and having a knuckle about which are mounted a pluralityof balls, the shaft being movable from a first position in which theballs are engaged in the tracks to lock the said one of the suspensionlinkages and the suspension lever arm together for pivotal movementabout the axis and a second position in which the balls are not engagedin the tracks and the said one of the suspension linkages and the otherend of the suspension lever arm are free to pivot about the axisrelative to one another.
 7. An amphibious vehicle as claimed in claim 6,in which the suspension disconnect apparatus comprises an actuator tomove the shaft between the first and second positions.
 8. An amphibiousvehicle as claimed in claim 7, in which the actuator is a hydraulicactuator.
 9. An amphibious vehicle as claimed in claim 5, in which thesaid one of the suspension linkages and the suspension lever arm haveadjacent drive portions, the suspension disconnect apparatus furthercomprising a sleeve having drive means for cooperation withcorresponding drive means on the drive portions, the sleeve beingmovable from a first position in which it is in driving cooperation withboth of the drive portions to lock the said one of the suspensionlinkages and the suspension lever arm together for pivotal movementabout the axis, and a second position in which it is in drivingcooperation with only one of the drive portions such that the linkageand the arm are free to pivot about the axis relative to one another.10. An amphibious vehicle as claimed in claim 9, in which the sleeve isinternally splined for engagement with corresponding splines formed onthe drive portions.
 11. An amphibious vehicle as claimed in claim 9, inwhich a bore of the sleeve has a non-circular cross section for drivingengagement with correspondingly shaped profiles on the drive portions.12. An amphibious vehicle as claimed in claim 9, in which the suspensiondisconnect apparatus comprises an actuator to move the sleeve betweenthe first and second positions.
 13. An amphibious vehicle as claimed inclaim 12, in which the actuator is an hydraulic actuator.
 14. Anamphibious vehicle as claimed in claim 5, in which the said one of thesuspension linkages and the suspension lever arm have correspondingdrive teeth, the suspension lever arm being movable between a firstposition in which the drive teeth are engaged so as to lock the said oneof the suspension linkages and the suspension lever arm together forpivotal movement about the axis, and a second position in which thedrive teeth are disengaged such that the said one of the suspensionlinkages and the suspension lever arm are free to pivot about the axisrelative to one another.
 15. An amphibious vehicle as claimed in claim14, in which the suspension disconnect apparatus comprises an actuatorto move the suspension lever arm between the first and second positions.16. An amphibious vehicle as claimed in claim 15, in which the actuatoris a hydraulic actuator.
 17. An amphibious vehicle as claimed in claim3, in which the vehicle further comprises a retraction disconnectapparatus for operatively connecting the retraction means to, oroperatively disconnecting the retraction means from, one of thesuspension linkages.
 18. An amphibious vehicle as claimed in claim 17,in which the retraction means-comprises a retraction actuatoroperatively connected to one end of a retraction lever arm, the otherend of the retraction lever arm being operatively connectable to saidone of the suspension linkages through the retraction disconnectapparatus.
 19. An amphibious vehicle as claimed in claim 18, in whichthe said one of the suspension linkages and the retraction lever arm aremounted to the vehicle body for pivotal movement relative to the vehiclebody about an axis, the retraction disconnect apparatus comprising meansfor locking the said one of the suspension linkages and the retractionlever arm together for pivotal, movement about the axis.
 20. Anamphibious vehicle as claimed in claim 19, in which the retractiondisconnect apparatus comprises a pneumatic clutch.
 21. An amphibiousvehicle as claimed in claim 20, in which the clutch inter-connects thesaid one of the suspension linkages and the retraction lever arm suchthat when the clutch is engaged the said one of the suspension linkagesand the retraction lever arm are locked together for pivotal movementabout the axis and that when the clutch is disengaged, the said one ofthe suspension linkages and the retraction lever arm are free to rotateabout the axis relative to one another.
 22. An amphibious vehicle asclaimed in claim 20, in which the said one of the suspension linkages isrotationally fast with a shaft, the pneumatic clutch having a firstcomponent which is also rotationally fast with the shaft and a secondcomponent attached so as to be rotationally fast with the retractionlever arm, the clutch being adapted such that when it is engaged thefirst and second components are rotationally fast so as to lock the saidone of the suspension linkages and the retraction lever arm together forpivotal movement about the axis.
 23. An amphibious vehicle as claimed inclaim 1, in which the wheel is connected to the vehicle body by an uppersuspension linkage and a lower suspension linkage.
 24. An amphibiousvehicle as claimed in claim 23, in which the suspension means isconnectable to the upper suspension linkage.
 25. An amphibious vehicleas claimed in claim 23, in which the suspension means is connectable tothe lower suspension linkage.
 26. An amphibious vehicle as claimed inclaim 24 or claim 25, in which the retraction means is connectable tothe lower suspension linkage.
 27. An amphibious vehicle as claimed inclaim 1, in which the suspension means comprises a strut having a coilspring mounted about a telescopic hydraulic damper.
 28. An amphibiousvehicle as claimed in claim 1, in which the retraction means comprises adouble acting fluid ram.
 29. An amphibious vehicle as claimed in 1, inwhich the retraction means comprises an electrically driven ram. 30.(canceled)
 31. An amphibious vehicle as claimed in claim 2, in which thewheel is mounted to the body of the vehicle by means of one or moresuspension linkages, the vehicle further comprising suspensiondisconnect apparatus for operatively connecting the suspension means to,or operatively disconnecting the suspension means from, one of thesuspension disconnect apparatus.